WO2018014443A1

WO2018014443A1 - Halogen-free phosphorus-containing silicon flame retardant, flame retardant transparent polycarbonate material, and preparation and use thereof

Info

Publication number: WO2018014443A1
Application number: PCT/CN2016/099238
Authority: WO
Inventors: 秦舒浩; 龙丽娟; 何文涛; 于杰; 李娟�; 向宇姝; 何敏
Original assignee: 江林（贵州）高科发展股份有限公司; 贵州省材料产业技术研究院
Priority date: 2016-07-18
Filing date: 2016-09-18
Publication date: 2018-01-25
Also published as: CN106009038B; CN106009038A

Abstract

A halogen-free flame retardant composition is prepared from a bridged derivative of DOPO via two phosphorus-carbon bonds and nanometer silica or a silica sol by means of solution blending or supercritical carbon dioxide blending.

Description

Halogen-free phosphorus-containing silicon flame retardant, flame-retardant transparent polycarbonate material, preparation and application thereof

Technical field

The invention relates to the field of flame retardants, in particular to a phosphorus-silicon-containing flame retardant and a transparent flame-retardant polycarbonate (PC) material containing the flame retardant, and to a flame retardant and a transparent resistor. Preparation methods and applications of burning PC materials.

Background technique

As a general-purpose engineering plastic, PC (polycarbonate) resin has excellent transparency and excellent mechanical properties, and therefore has been widely used in various fields of production and life. However, in order to meet some applications, such as in electrical and electronic applications (such as housings and components of appliances and equipment), flame retardancy is an important property. However, the flame retardancy of the unmodified PC resin can only reach UL94V-2 level, which limits its use in these fields to some extent. In addition, with the development of industries such as automotive and electronic communication, the flame retardant performance requirements of plastic parts of products are getting higher and higher, and many manufacturers have to clearly meet the requirements of UL-94V-0 for the flame retardant grade of their plastic parts, and Many applications also require the PC to maintain good transparency, which requires flame retardant modification without affecting the original transparency of the PC.

Conventional halogen flame retardant PC materials often require the addition of cerium oxide as a synergist, and this synergist can easily cause degradation of the main chain in the PC resin, resulting in degradation of PC material properties and gas embossing on the surface of PC materials. The defect, and the halogen flame-retardant PC material completely loses the light transmittance of the PC resin, and the resulting PC material has low light transmittance.

Phosphorus-nitrogen flame retardants also make PCs opaque due to their large amount, and have a great influence on the mechanical properties of materials. Boron compounds will form a three-dimensional network structure during processing, which will also affect the transparency of PC and be flame retardant. It is not efficient and usually only works with polysiloxane to achieve better results.

Organic phosphate ester flame retardants are widely used in the flame retardant modification of PC materials because of their low price, good flame retardant effect and halogen-free environmental protection. However, organic phosphate flame retardants are mostly liquid or have a very high melting point. Low solids, the amount of addition should reach 15%-25% to obtain the desired flame retardant effect. A large number of organophosphate flame retardants have obvious plasticizing effect on PC materials, thus greatly reducing the PC material. Heat resistance level; at the same time, PC materials prepared with organic phosphate flame retardants are not toughened with additional In the case of the agent, its toughness is not satisfactory, which seriously affects the mechanical properties and transparency of the PC material.

Since phospho-carbon bond-containing compounds have good thermal stability and chemical stability, phosphonate halogen-free flame retardants have been used. For example, dialkyl phosphinates are used as flame retardants for nylons and polyesters. However, the dialkyl phosphinate makes the PC completely opaque.

The phosphonate flame retardant mainly contains a derivative of a phosphorus-carbon bond bridge 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), which contains 2 molecules in one molecule. Phosphorus center (DiDOPO) with good thermal stability and flame retardancy. In recent years, phosphorus-carbon bonded bridged DOPO derivatives have attracted more and more attention due to their high thermal stability, high phosphorus content and high flame retardant efficiency. Patent CN201410333261.5 discloses the application of a class of bridge chain DOPO derivatives in PC, but the PC is rendered translucent due to the large amount of addition.

Summary of the invention

In the prior art, there is no phosphorus-carbon bonded phosphorus-silicone flame-retardant PC material which is flame-retardant, high-efficiency, safe, flame retardant and transparent PC material dispersed well, has good mechanical properties, and has both flame retardancy and transparency properties.

The technical problem solved by the invention is to overcome the defects in the prior art, and to provide a transparent flame-retardant PC material which is convenient to add, flame-retardant, efficient, safe, advantageous for dispersing and maintaining good mechanical properties and a preparation method thereof.

In the prior art, the inventors have not found that a phosphorus-carbon bridged DOPO derivative is recrystallized on the surface of a nanosilica powder or a silica sol by a solution blending or supercritical carbon dioxide method to prepare a flame retardant composition.

Specifically, in view of the deficiencies of the prior art, the present invention provides the following technical solutions:

A halogen-free flame retardant composition comprising a double phosphorus-carbon bond bridge chain DOPO derivative and a nano silica or silica sol, wherein the double phosphorus-carbon bond bridge chain DOPO derivative is dispersed in nano silica or Silica sol surface.

Preferably, wherein the mass ratio of the double phosphorus-carbon bond bridge chain DOPO derivative to the nano silica or silica sol is (3-5):1.

Preferably, wherein the double phosphorus-carbon bond bridge chain DOPO derivative is a DOPO derivative represented by the following structural formula (I):

Preferably, R1 is a C6-C18 aryl group, preferably selected from the group consisting of phenethyl, naphthylethyl, p-phenylethyl, phenylpropyl.

Here, the "C6-C18" means that the number of carbon atoms is 6-18.

Preferably, the nano silica or silica sol has an average particle diameter of 10 nm to 100 nm.

In addition, the present invention also provides a halogen-free flame-retardant transparent polycarbonate material characterized by comprising the following components:

85-95 parts by weight of polycarbonate and 5-15 parts by weight of the flame retardant composition according to any one of claims 1 to 4.

Preferably, for the flame retardant composition or the polycarbonate material, the flame retardant composition is obtained by the following preparation method:

Dissolving the DOPO derivative in an organic solvent to form a solution, adding nano silica or silica sol, mixing the solution with nano silica or silica sol, heating to evaporate the solvent, thereby recrystallizing the DOPO derivative Dispersion on the surface of the nanosilica or silica sol thereby obtaining a flame retardant composition.

Preferably, for the flame retardant composition or the polycarbonate material, wherein the flame retardant composition is obtained by the following preparation method:

Dissolving the DOPO derivative in an organic solvent to form a solution, adding nano silica or a silica sol, and blending the solution with nano silica or silica sol in the presence of supercritical carbon dioxide to evaporate the solvent. The DOPO derivative is recrystallized and dispersed on the surface of the nano silica or silica sol to thereby obtain a flame retardant composition.

Preferably, the polycarbonate material is obtained by the following production method, and the PC resin and the flame retardant composition are mixed and then subjected to melt blend extrusion molding.

Preferably, for the polycarbonate material, the preparation method comprises the following steps:

(a) after drying the PC resin, mixing with the flame retardant composition to form a raw material;

(b) the raw material obtained in step (a) is added to a twin-screw extruder for melt blending extrusion, the temperature of each zone of the twin-screw extruder is from 250 ° C to 280 ° C;

(c) The step (b) melt-blending the extruded material is subjected to drawing and pelletizing to obtain a halogen-free flame-retardant transparent polycarbonate material.

Preferably, for the polycarbonate material, the preparation method further comprises the step (i) before the step (a): drying the PC resin at 120 ° C to 140 ° C.

Preferably, for the polycarbonate material, in step (b) of the preparation method, the twin-screw extruder has five different temperature control zones.

Furthermore, the present invention also provides a method for preparing a flame retardant composition, which is obtained by the following preparation method: dissolving a phosphorus-carbon bridged DOPO derivative in an organic solvent to form a solution, adding nano silica or a silica sol, the solution is mixed with nano silica or silica sol, heated to 50-120 ° C to evaporate the solvent, whereby the DOPO derivative is recrystallized and dispersed on the surface of the nano silica or silica sol to thereby obtain flame retardant Composition.

Furthermore, the present invention also provides a method for preparing a flame retardant composition, which is obtained by the following preparation method: dissolving a phosphorus-carbon bridged DOPO derivative in an organic solvent to form a solution, adding nano silica or a silica sol, which is blended with nano silica or silica sol in the presence of supercritical carbon dioxide to evaporate the solvent, whereby the DOPO derivative is recrystallized and dispersed on the surface of the nano silica or silica sol A flame retardant composition is obtained.

Preferably, the method for preparing a flame retardant composition, wherein the supercritical carbon dioxide pressure is 10-30 MPa, preferably 20 MPa, and the temperature is 20 when the solution is blended with nano silica or silica sol. -60 ° C.

Preferably, the method for preparing the flame retardant composition, wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetone, ethylene glycol, propylene glycol, dimethyl ether, diethyl ether, and ethylene One or more of alcohol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, and propylene glycol monoethyl ether.

Furthermore, the present invention also provides a method for preparing a halogen-free flame-retardant transparent polycarbonate material, which comprises the following steps:

(a) A flame retardant composition or a front surface according to any of the preceding claims after drying the polycarbonate resin The flame retardant composition obtained by any one of the preparation methods is mixed to form a raw material;

In addition, the invention also provides the use of the flame retardant composition or the polycarbonate material described in an electrical device housing or automotive plastic component.

The invention utilizes supercritical carbon dioxide to separate the nano silica or silica sol particles to reduce agglomeration; or to recrystallize the bridged DOPO derivative on the surface of the nanoparticle by volatilizing the solvent by heating the solvent, and using the large ratio of the nano silica particles The surface area increases the flame retardant efficiency of the bridged DOPO derivative. In addition, nano-silica also acts as a synergistic flame retardant.

DRAWINGS

Figure 1 is a ¹ H NMR spectrum of the DOPO derivative of the formula (I) when R is a phenethyl group synthesized in the examples;

Figure 2 is a ³¹ P NMR spectrum of the DOPO derivative of the formula (I) when R is a phenethyl group synthesized in the examples;

Figure 3 is an infrared spectrum diagram of the DOPO derivative of the formula (I) when R is a phenethyl group synthesized in the examples;

Figure 4 is a mass spectrum of the DOPO derivative of the formula (I) when R is a phenethyl group synthesized in the examples;

Figure 5 is a ³¹ P NMR spectrum of the DOPO derivative of the formula (I) when R is a naphthylethyl group synthesized in the examples;

Figure 6 is a mass spectrum of the DOPO derivative of the formula (I) when R is a naphthylethyl group synthesized in the examples;

Figure 7 is an infrared spectrum of the DOPO derivative of the formula (I) when R synthesized in the examples is a naphthylethyl group.

detailed description

In a preferred embodiment of the present invention, the halogen-free transparent flame-retardant PC material of the present invention comprises a PC resin and a flame retardant composition, and the PC resin accounts for 85% to 95% by mass percentage. The fuel composition is 5% to 15%. Among them, it is preferred that the flame retardant composition is a composite composition of a phosphorus-carbon bridged DOPO derivative and a nano silica or a silica sol, and has a mass ratio of 3 to 5:1.

In a preferred embodiment of the present invention, the flame retardant composition of the present invention is prepared by dissolving a phosphorus-carbon bridged DOPO derivative in an organic solvent and then blending conditions in supercritical carbon dioxide or solution. The lower recrystallized on the surface of the nano silica or silica sol forms a nanocomposite flame retardant composition.

In the present invention, the nano silica used is a nanosilica solid powder, which is commercially available.

In a preferred embodiment of the invention, the specific preparation method of the polycarbonate material is as follows:

(1) drying the PC resin at a temperature of 120 ° C - 140 ° C for 2-8 h;

(2) dissolving a bridged-chain DOPO derivative (wherein R1 is preferably selected from the group consisting of phenethyl, naphthylethyl, p-phenylethyl, phenylpropyl) in an organic solvent at a reflux temperature, The solution is then mixed with nano-silica or silica sol using solution blending or mixed under supercritical carbon dioxide conditions to evaporate the solvent, and the bridged DOPO derivative is recrystallized into the nano-silica during solvent evaporation. Or a silica sol surface, thereby obtaining a flame retardant composition, wherein the ratio of the bridged DOPO derivative to the nano silica is 3 to 5:1, the supercritical carbon dioxide blending pressure is 20 MPa, and the time is 2 to 6 hours;

(3) weighing the PC resin and the flame retardant composition of the formulation ratio, and mixing uniformly;

(4) The raw material after the step (3) is added to a twin-screw extruder for melt blending extrusion, the temperature of each zone of the twin-screw extruder is 250 ° C - 280 ° C;

(5) The raw material extruded through the step (4) is subjected to drawing, cooling, and pelletizing processes to obtain a transparent flame-retardant PC material.

Operating parameters control of the twin-screw extruder: the temperature is from 250-280 ° C from the feeding section to the head, and the screw speed is 300-400 rpm.

Hereinafter, a method for producing a halogen-free flame-retardant transparent polycarbonate material of the present invention will be specifically described by way of examples.

The instruments and reagents used in the examples are as follows:

I. Instruments and reagents

Instrument

Twin-screw extruder: sold by Coperion Koya (Nanjing) Machinery Manufacturing Co., Ltd., model CTE35; operating parameter control: temperature from the feeding section to the head is 250-280 ° C, screw speed is 300-400 rpm.

Injection molding machine: sold by Zhende Plastic Machinery Factory, model CJ80MZ2NCII

Melt index test instrument: sold by Chengde Jinjian Testing Instrument Co., Ltd., model XNR-400C

Tensile yield strength, elongation at break, flexural strength and flexural modulus test equipment: Model WDW-10C

Cantilever beam notched impact strength test instrument: Shenzhen SANS Vertical and Horizontal Technology Co., Ltd. PTM1000

Flame-retardant performance test method: UL-94 vertical burning test is adopted. When testing, the end of the sample is clamped vertically, and the Bunsen burner (flame height 20±1mm) is applied to the free end of the sample for 10s, and the flame is removed. After recording the sample with flame burning time, if the sample has a flame burning time of less than 30s, continue to apply the second flame for 10s, remove the flame and record the first flaming burning time t1 of the sample, the second flaming combustion Time t2.

2. Reagent

PC resin: Mitsubishi s-2001r;

PCPO chain-containing DOPO derivative: a compound represented by the formula (I), wherein the specific R1 is H or an aryl group or the like, and specifically, R1 used in all the following examples is a phenethyl group or a naphthylethyl group. The DOPO derivative represented by (I) is prepared by the following preparation method:

DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide), acetophenone was added to xylene in a molar ratio of 2:1, heated to 150 ° C to dissolve, and then slowly A 1/3 molar ratio of acetophenone to phosphorus oxychloride was added, and the mixture was reacted for 20 hours, cooled, and isopropanol was added thereto, followed by stirring under reflux. After standing for a while, the product was largely precipitated, suction filtered, and washed to give a white powder product.

1 to 7 are the spectra of the DOPO derivative represented by the formula (I) wherein R1 is phenethyl or naphthylethyl prepared by the above preparation method, and the structure thereof is identified; specifically, FIG. 1 Is the ¹ H NMR hydrogen spectrum of the DOPO derivative in which R is phenethyl, and it can be seen from the figure that Ar-H:CH:CH ₂ =21:1:2, the number of hydrogen and the molecular structure of the phenethyl derivative The number of hydrogens is consistent; FIG. 2 is a ³¹ P NMR nuclear magnetic spectrum of a DOPO derivative in which R is a phenethyl group, from which it can be seen that δ=34-38 ppm is the phosphorus shift peak of the product, and the raw material DOPO (δ=15 ppm) The phosphorus shift peak did not appear, indicating that the starting material had been completely converted. Figure 3 is an infrared spectrum of the DOPO derivative in which R is phenethyl. From this figure, it can be seen that 3000 to 2800 cm ^-1 is the bridge group in the molecular structure of the product. The CH ₂ characteristic absorption peak indicates that the bridging group has been successfully introduced into the molecular structure of the product; FIG. 4 is a mass spectrum of the DOPO derivative in which R is a phenethyl group, from which it can be seen that m/z 534 is molecular mass peak phenethyl DOPO derivatives, synthetic molecules can be clearly successful structure; FIG. 5 is R is a ³¹ P NMR spectrum of phosphorus DOPO derivative naphthylethyl group, The figure shows that δ=35-38 ppm is the phosphorus shift peak of the product; FIG. 6 is a mass spectrum of the DOPO derivative in which R is naphthylethyl, from which it can be seen that m/z 584 is a naphthylethyl DOPO derivative. Molecular mass spectrum peak; Fig. 7 is an infrared spectrum of a DOPO derivative in which R is a naphthylethyl group. It can be seen from the figure that 3000 to 2800 cm ^-1 also refers to a CH ₂ characteristic absorption peak of a bridge group. Combined with ³¹ P NMR, mass spectrometry and infrared analysis, it was confirmed that the naphthalene ethyl bridged DOPO derivative has been successfully synthesized.

Among them, the types and conditions of instruments such as nuclear magnetic, infrared, and mass spectrometry used in the characterization of the structure described above are as follows:

NMR nuclear magnetic resonance spectrum: Bruker Avance 400 NMR tester, deuterated chloroform as a solvent.

NMR nuclear magnetic phosphorus spectrum: Bruker Avance 400 NMR tester, deuterated chloroform as solvent, 85% phosphoric acid as a positioning standard.

Infrared: potassium bromide powder tableting method, Nicolet 1N10MX infrared spectrum tester

Mass Spectrometry: EI Method, PerkinElmer Mass Spectrometer

Nano-silica: nanometer particle size range of 10-100nm, Shenzhen Crystal Chemicals for sale;

Silica Sol: sold by DuPont, USA, with a particle size of 15-30 nm.

2. Preparation of flame retardant transparent polycarbonate material

Example 1

(1) Commercially available PC resin was dried at a temperature of 120 ° C for 4 h.

(2) The DOPO compound represented by the above formula (I) wherein R1 is a phenethyl group is dissolved in an ethanol solvent under reflux at a temperature of 60 ° C, wherein the mass ratio of the DOPO compound to the solvent is 1:10, The nano silica was added and blended under supercritical carbon dioxide conditions at 20 ° C and 20 MPa to obtain a flame retardant composition. Wherein, the mass ratio of the DOPO compound to the nano silica is 4:1, the supercritical carbon dioxide pressure is 20 MPa, and the time is 4 h.

(3) The PC resin/flame retardant composition obtained in the step (1) was weighed and mixed at a mass ratio of 90/10 to form a raw material of 1 kg.

(4) The raw material after the step (3) is fed into a twin-screw extruder for melt blending extrusion; wherein the twin-screw extruder has a 5-stage temperature control zone, wherein the temperature of each zone is 250 ° C, 260 °C, 265 ° C, 270 ° C, 275 ° C, the head temperature was 275 ° C, and the screw speed was 300 rpm.

(5) The raw material extruded through the step (4) is subjected to drawing, cooling, and pelletizing to obtain a transparent flame-retardant PC material.

(6) The obtained transparent PC material was injection molded under an injection molding machine (injection temperature was 265 ° C) into mechanical splines having thicknesses of 1.5 mm and 3.0 mm, and performance tests were performed.

The unextended commercial PC material in the step (1) of Example 1 was subjected to the same extrusion and post-treatment methods as the sample obtained in Comparative Example 1 in the steps (4) and (5) of Example 1. The performance test was performed in comparison with the sample performance test results of Example 1 in Table 1 below.

Table 1 Performance comparison between transparent PC materials prepared by the present invention and ordinary PC materials

Example 2:

(1) Commercially available PC resin was dried at a temperature of 140 ° C for 2 h.

(2) Dissolving the DOPO compound represented by the above formula (I) wherein R1 is a naphthylethyl group in a propanol solvent at a temperature of 60 ° C, wherein the mass ratio of the DOPO compound to the solvent is (1:10) , Further, after adding nano-silica and then blending with nano-silica at a temperature of 60 ° C and heating to a temperature of 90 ° C to evaporate the solvent, a flame retardant composition is obtained. Wherein, the mass ratio of the DOPO compound to the nano silica is 3:1, and the time is 5 hours.

(3) The PC resin/flame retardant composition obtained in the step (1) was weighed and mixed in a mass ratio of 85/15 to form a raw material of 1 kg.

(4) The raw material after the step (3) is fed into a twin-screw extruder for melt blending extrusion; wherein the twin-screw extruder has a 5-stage temperature control zone, wherein the temperature of each zone is 255 ° C, 265 °C, 270 ° C, 275 ° C, 280 ° C, the head temperature was 275 ° C, and the screw speed was 300 rpm.

(6) The obtained transparent PC material was injection-molded under an injection molding machine (injection temperature of 250 ° C) into mechanical splines having thicknesses of 1.5 mm and 3.0 mm, and performance tests were performed.

The unextended commercial PC material in the step (1) of Example 1 was subjected to the same extrusion and post-treatment methods as the sample obtained in Comparative Example 1 in the steps (4) and (5) of Example 1. The performance test was performed in comparison with the sample performance test results of Example 2 in Table 2 below.

Table 2 Performance comparison between transparent PC materials prepared by the present invention and ordinary PC materials

Example 3:

(1) A commercially available PC resin was dried at a temperature of 130 ° C for 6 hours.

(2) Dissolving the DOPO compound represented by the above formula (I) wherein R1 is a naphthylethyl group in an acetone solvent at a temperature of 60 ° C, wherein the mass ratio of the DOPO compound to the solvent is 1:8, and then adding The nanosilica sol is further blended with the nanosilica sol at a temperature of 25 ° C and then heated to a temperature of 50 ° C to evaporate the solvent to obtain a flame retardant composition. Wherein, the DOPO compound and the silica sol have a mass ratio of 5:1 and a time of 5 h.

(3) The PC resin/flame retardant composition obtained in the step (1) was weighed and mixed in a mass ratio of 95/5 to form a raw material of 1 kg.

(6) The obtained transparent PC material was injection molded under an injection molding machine (injection temperature of 245 ° C) into mechanical splines having thicknesses of 1.5 mm and 3.0 mm, and performance tests were performed.

The unextended commercial PC material in the step (1) of Example 1 was subjected to the same extrusion and post-treatment methods as the sample obtained in Comparative Example 1 in the steps (4) and (5) of Example 1. The performance test was performed in comparison with the sample performance test results of Example 3 in Table 3 below.

Table 3 Performance comparison between transparent PC materials prepared by the present invention and ordinary PC materials

Example 4:

(1) A commercially available PC resin was dried at a temperature of 130 ° C for 8 hours.

(2) Dissolving the DOPO compound represented by the above formula (I) wherein R1 is a naphthylethyl group in a propylene glycol solvent at a temperature of 60 ° C, wherein the mass ratio of the DOPO compound to the solvent is 1:15, and then adding After the nanosilica sol is further blended with the nanosilica sol at a temperature of 60 ° C, the solvent is evaporated under heating to a temperature of 120 ° C to obtain a flame retardant composition. Wherein, the DOPO compound and the silica sol have a mass ratio of 5:1 and a time of 5 h.

The unextended commercial PC material in the step (1) of Example 1 was subjected to the same extrusion and post-treatment methods as the sample obtained in Comparative Example 1 in the steps (4) and (5) of Example 1. The performance test was performed in comparison with the sample performance test results of Example 3 in Table 4 below.

Table 4 Comparison of performance between transparent PC materials prepared by the present invention and ordinary PC materials

Comparative Example 2 and Comparative Example 3:

The same reagents and method steps as in Example 1 were employed except that the mass ratio of DOPO to nanosilica was changed to 2:1 and 6:1 in step (2), respectively, in the same manner as in Example 1. The PC material was modified, and the obtained sample was tested in the same manner as in Example 1. The test results are shown in Table 5 below:

Table 5 Performance of modified PC material after modification in Example 5

As can be seen from the above comparative examples, the ratio of the ratio of the DOPO derivative to the silica in the flame retardant composition of the present invention is in the range of (3-5):1, and its performance is optimal.

Claims

A halogen-free flame retardant composition comprising a double phosphorus-carbon bond bridge chain DOPO derivative and a nano silica or silica sol, wherein the double phosphorus-carbon bond bridge chain DOPO derivative is dispersed in nano silica or Silica sol surface.
The flame retardant composition according to claim 1, wherein the mass ratio of the double phosphorus-carbon bond bridge DOPO derivative to the nano silica or silica sol is (3-5):1.
The flame retardant composition according to claim 1 or 2, wherein the double phosphorus-carbon bond bridged DOPO derivative is a DOPO derivative represented by the following structural formula (I):

Wherein R1 is a C6-C18 aryl group, preferably selected from the group consisting of phenethyl, naphthylethyl, p-phenylethyl, phenylpropyl.
The flame retardant composition according to any one of claims 1 to 3, wherein the nano silica or silica sol has an average particle diameter of from 10 nm to 100 nm.
A halogen-free flame-retardant transparent polycarbonate material characterized by comprising the following components:

85-95 parts by weight of polycarbonate and 5-15 parts by weight of the flame retardant composition according to any one of claims 1 to 4.
The flame retardant composition according to any one of claims 1 to 4, or the polycarbonate material according to claim 5, wherein the flame retardant composition is obtained by the following production method:

Dissolving the DOPO derivative in an organic solvent to form a solution, adding nano silica or silica sol, mixing the solution with nano silica or silica sol, heating to evaporate the solvent, thereby recrystallizing the DOPO derivative Dispersion on the surface of the nanosilica or silica sol thereby obtaining a flame retardant composition.
The flame retardant composition according to any one of claims 1 to 4, or the polycarbonate material according to claim 5, wherein the flame retardant composition is obtained by the following production method:

Dissolving the DOPO derivative in an organic solvent to form a solution, adding nano silica or a silica sol, and blending the solution with nano silica or silica sol in the presence of supercritical carbon dioxide to evaporate the solvent. The DOPO derivative is recrystallized and dispersed on the surface of the nano silica or silica sol to thereby obtain a flame retardant composition.
The polycarbonate material according to any one of claims 5 to 7, which is obtained by the following production method, which is obtained by mixing a PC resin and the flame retardant composition, followed by melt blending and extrusion molding.
The polycarbonate material according to claim 8, wherein the preparation method comprises the steps of:

(a) after drying the PC resin, mixing with the flame retardant composition to form a raw material;

(b) the raw material obtained in step (a) is added to a twin-screw extruder for melt blending extrusion, the temperature of each zone of the twin-screw extruder is from 250 ° C to 280 ° C;

(c) The step (b) melt-blending the extruded material is subjected to drawing and pelletizing to obtain a halogen-free flame-retardant transparent polycarbonate material.
The polycarbonate material according to claim 9, wherein the preparation method further comprises the step (i) before the step (a): drying the PC resin at 120 ° C to 140 ° C.
The polycarbonate material according to claim 9 or 10, wherein in the step (b) of the preparation method, the twin-screw extruder has five different temperature control zones.
A method for preparing a flame retardant composition, which is obtained by the following preparation method: dissolving a phosphorus-carbon bridged DOPO derivative in an organic solvent to form a solution, adding a nano silica or a silica sol, and the solution is The nano silica or silica sol is mixed, heated to 50-120 ° C to evaporate the solvent, whereby the DOPO derivative is recrystallized and dispersed on the surface of the nano silica or silica sol to thereby obtain a flame retardant composition.
A method for preparing a flame retardant composition, which is obtained by the following preparation method: dissolving a phosphorus-carbon bridged DOPO derivative in an organic solvent to form a solution, adding a nano silica or a silica sol, in supercritical carbon dioxide The solution is blended with nano silica or silica sol in the presence of a solvent to evaporate the solvent, whereby the DOPO derivative is recrystallized and dispersed on the surface of the nanosilica or silica sol to thereby obtain a flame retardant composition.
The method for producing a flame retardant composition according to claim 13, wherein the solution and the solution When the nano silica or silica sol is blended, the supercritical carbon dioxide pressure is 10-30 MPa, preferably 20 MPa, and the temperature is 20-60 °C.
The production method according to any one of claims 12 to 14, wherein the organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropanol, acetone, ethylene glycol, propylene glycol, dimethyl ether, diethyl ether, and B. One or more of diol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, and propylene glycol monoethyl ether.
A method for preparing a halogen-free flame-retardant transparent polycarbonate material, comprising the steps of:

(a) mixing the flame retardant composition obtained by the method according to any one of claims 1 to 4 or the flame retardant composition obtained by the method according to any one of claims 12 to 15 after drying the polycarbonate resin to form a raw material ;

(b) the raw material obtained in step (a) is added to a twin-screw extruder for melt blending extrusion, the temperature of each zone of the twin-screw extruder is from 250 ° C to 280 ° C;

(c) The step (b) melt-blending the extruded material is subjected to drawing and pelletizing to obtain a halogen-free flame-retardant transparent polycarbonate material.
Use of the flame retardant composition of any of claims 1-4 or the polycarbonate material of any of claims 5-11 in an electrical equipment enclosure or automotive plastic component.